Python Sheet Cheat Sheet

while True:
      user_input = input('Enter a number: ')
      number = int(user_input)
      print('The number squared is', number ** 2')

if 3 < 2: #if statement must compare 2 Boolean\
     print('3 is less than 2') 
elif 4 < 2: #can't have 0 or more elif statement
     print('4 is less than 2')
elif 5 < 2:
     print('5 is less than 2')
else: #can have 0 or 1 else statement at the end
     print('none of the above are True')

thelist = [4, 3, 2, 1, 0]
index = 0 # start at the first item
while index < len(thelist):
    print (thelist[index]) #prints each item
    index = index + 1

forlist = [3, 4, 5, 2, 1]
for item in forlist:
    print(item) 
  

#function with no parameters/arguments
#and no return value
#return is optional if you do not return a value
def nameOfFunction():
    print (‘This function has no parameters’)
    print (‘This function has no return value’)
    return # no value, just exits the function
                        ______________________________________ 
#function call
nameOfFunction()
#function with 1 parameter/argument
def testFunction(param):
    print (‘This function has 1 parameter’)
    print (param) 

#function call
testFunction (“this is the parameter value”)           ______________________________________
#function with 2 parameters and a return value
def function3(param1, param2):
    print(‘This function has 2 parameters’)
    return param1 + param2 # return value
#function call and store the result in a variable
returnValue = function3(2, 3)
print (returnValue) 

#repeatly receives positive integers from user and exit when gets negative number, then count even and odd number

evenCount = 0
oddCount = 0

while True:
     user_input = int(input("Enter number: "))
     if user_input < 0:
         print("Total even: ",evenCount)
         print("Total odd: ",oddCount)
         break
elif user_input > 0:
     if user_input % 2 == 0:
         evenCount = evenCount + 1
     else:
         oddCOunt = oddCount +1

' ' '
expected output:
0
01
012
0123
01234
' ' '
mystring = " "
count = 0
while count < 5:
     mystring = mystring + str(count)
     print(mrstring)
     count = count + 1

count = 0 #start at 0
while count < 10: #loop while count is less than 10
       print(count) #will print number 0-9
       count = count + 1 #must increase count
' ' '
output
0
to
9
' ' '

user_number = input("What number do you want to count down? ")
number = int(user_number)
countdown_string = ' '

while number > 0:
      countdown_number = countdown_string + str(number) + " "
      number = number - 1
#print(number)

print(countdown_string)

import random

#create a list
mylist = [-1,1.2,11,"srujryju","yikjghk"]
random_item = random.choice(mylist)
print(mylist, random_item)

while True:
      word = input("Please enter a word")
      index = 0
      reverse = ' '

while int(index) < len(word):
     reverse = word[index] + (reverse)
     index = int(index) + 1

print ("Reverse: ", reverse)

def areaoscircle(r):
      pi = 3.1415
      return pi * r ** 2